20531666 has 8 divisors (see below), whose sum is σ = 32418480. Its totient is φ = 9725508.

The previous prime is 20531659. The next prime is 20531669. The reversal of 20531666 is 66613502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20531669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 270116 + ... + 270191.

It is an arithmetic number, because the mean of its divisors is an integer number (4052310).

Almost surely, 2^20531666 is an apocalyptic number.

20531666 is a deficient number, since it is larger than the sum of its proper divisors (11886814).

20531666 is a wasteful number, since it uses less digits than its factorization.

20531666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540328.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 20531666 is about 4531.1881444054. The cubic root of 20531666 is about 273.8260301873.

The spelling of 20531666 in words is "twenty million, five hundred thirty-one thousand, six hundred sixty-six".